Transmission of masticatory load in mandibular implant-retained overdentures was evaluated using a three-dimensional finite element model. The reaction forces on the distal edentulous mucosa and the stress on the peri-implant bone were compared in overdentures retained either by two ball attachments or by two clips on a bar connecting two implants. In the finite element model, a 35 N load on the first mandibular molar induced a greater reaction force on the distal edentulous ridge mucosa of the nonworking side when the overdenture was anchored by ball attachments than with the clips/bar attachment. Stress on peri-implant bone was greater with the clips/bar attachment than with the ball attachment. Keywords: ball attachment, clips/bar attachment, finite element model, implants, overdenture, reaction forces, stress